Folding screen



FIG. 1 is a perspective view of a folding screen, showing the claimed design;

FIG. 2 is a top plan view thereof;

FIG. 3 is a left side view thereof;

FIG. 4 is a front elevational view thereof;

FIG. 5 is a right side view thereof;

FIG. 6 is a rear elevational view thereof; and,

FIG. 7 is a bottom plan view thereof.

The broken lines shown in FIG. 6 depict portions of the folding screen that form no part of the claimed design. 

CLAIM The ornamental design for a folding screen, as shown and described. 